package com.andreabaccega.edittextformexample;

import android.annotation.TargetApi;
import android.content.Context;
import android.content.res.Configuration;
import android.os.Build;
import android.os.Bundle;
import android.preference.ListPreference;
import android.preference.Preference;
import android.preference.PreferenceActivity;
import android.preference.PreferenceCategory;
import android.preference.PreferenceFragment;
import android.preference.PreferenceManager;

/**
 * A {@link PreferenceActivity} that presents a set of application settings. On handset devices, settings are presented
 * as a single list. On tablets, settings are split by category, with category headers shown to the left of the list of
 * settings.
 * <p>
 * See <a href="http://developer.android.com/design/patterns/settings.html"> Android Design: Settings</a> for design
 * guidelines and the <a href="http://developer.android.com/guide/topics/ui/settings.html">Settings API Guide</a> for
 * more information on developing a Settings UI.
 */
public class SettingsActivity
    extends PreferenceActivity
{
	/**
	 * Binds a preference's summary to its value. More specifically, when the preference's value is changed, its summary
	 * (line of text below the preference title) is updated to reflect the value. The summary is also immediately
	 * updated upon calling this method. The exact display format is dependent on the type of preference.
	 * 
	 * @see #sBindPreferenceSummaryToValueListener
	 */
	private static void bindPreferenceSummaryToValue( Preference preference )
	{
		// Set the listener to watch for value changes.
		preference.setOnPreferenceChangeListener( SettingsActivity.sBindPreferenceSummaryToValueListener );

		// Trigger the listener immediately with the preference's current value.
		String newValue = PreferenceManager.getDefaultSharedPreferences( preference.getContext() ).getString( preference.getKey(), "" );
		SettingsActivity.sBindPreferenceSummaryToValueListener.onPreferenceChange( preference, newValue );
	}

	/**
	 * Determines whether the simplified settings UI should be shown. This is true if this is forced via
	 * {@link #ALWAYS_SIMPLE_PREFS}, or the device doesn't have newer APIs like {@link PreferenceFragment}, or the
	 * device doesn't have an extra-large screen. In these cases, a single-pane "simplified" settings UI should be
	 * shown.
	 */
	private static boolean isSimplePreferences( Context context )
	{
		return SettingsActivity.ALWAYS_SIMPLE_PREFS || Build.VERSION.SDK_INT < Build.VERSION_CODES.HONEYCOMB
		    || !SettingsActivity.isXLargeTablet( context );
	}

	/**
	 * Helper method to determine if the device has an extra-large screen. For example, 10" tablets are extra-large.
	 */
	private static boolean isXLargeTablet( Context context )
	{
		return ( context.getResources().getConfiguration().screenLayout & Configuration.SCREENLAYOUT_SIZE_MASK ) >= Configuration.SCREENLAYOUT_SIZE_XLARGE;
	}

	/** {@inheritDoc} */
	@Override
	public boolean onIsMultiPane()
	{
		return SettingsActivity.isXLargeTablet( this ) && !SettingsActivity.isSimplePreferences( this );
	}

	/**
	 * Set up the {@link android.app.ActionBar}, if the API is available.
	 */
	@TargetApi( Build.VERSION_CODES.HONEYCOMB )
	private void setupActionBar()
	{
		if ( Build.VERSION.SDK_INT >= Build.VERSION_CODES.HONEYCOMB )
		{
			// Show the Up button in the action bar.
			getActionBar().setDisplayHomeAsUpEnabled( true );
		}
	}

	/**
	 * Shows the simplified settings UI if the device configuration if the device configuration dictates that a
	 * simplified, single-pane UI should be shown.
	 */
	@SuppressWarnings( "deprecation" )
	private void setupSimplePreferencesScreen()
	{
		if ( !SettingsActivity.isSimplePreferences( this ) )
		{
			return;
		}

		// Class<ContactPreferenceFragment> a = ContactPreferenceFragment.class;

		// In the simplified UI, fragments are not used at all and we instead
		// use the older PreferenceActivity APIs.

		// Add 'general' preferences.
		PreferenceCategory fakeHeader = new PreferenceCategory( this );
		addPreferencesFromResource( R.xml.pref_contact );

		SettingsActivity.bindPreferenceSummaryToValue( findPreference( SettingsActivity.PREF_KEY_FULL_NAME ) );
		SettingsActivity.bindPreferenceSummaryToValue( findPreference( SettingsActivity.PREF_KEY_ADDRESS ) );
		SettingsActivity.bindPreferenceSummaryToValue( findPreference( SettingsActivity.PREF_KEY_PHONE_NUMBER ) );
		SettingsActivity.bindPreferenceSummaryToValue( findPreference( SettingsActivity.PREF_KEY_EMAIL ) );
	}

	@Override
	protected void onCreate( Bundle savedInstanceState )
	{
		super.onCreate( savedInstanceState );
		setupActionBar();
	}

	@Override
	protected void onPostCreate( Bundle savedInstanceState )
	{
		super.onPostCreate( savedInstanceState );

		setupSimplePreferencesScreen();
	}

	/**
	 * This fragment shows general preferences only. It is used when the activity is showing a two-pane settings UI.
	 */
	@TargetApi( Build.VERSION_CODES.HONEYCOMB )
	public static class ContactPreferenceFragment
	    extends PreferenceFragment
	{

		@Override
		public void onCreate( Bundle savedInstanceState )
		{
			super.onCreate( savedInstanceState );
			addPreferencesFromResource( R.xml.pref_contact );

			// Bind the summaries of EditText/List/Dialog/Ringtone preferences
			// to their values. When their values change, their summaries are
			// updated to reflect the new value, per the Android Design
			// guidelines.
			SettingsActivity.bindPreferenceSummaryToValue( findPreference( SettingsActivity.PREF_KEY_FULL_NAME ) );
			SettingsActivity.bindPreferenceSummaryToValue( findPreference( SettingsActivity.PREF_KEY_ADDRESS ) );
			SettingsActivity.bindPreferenceSummaryToValue( findPreference( SettingsActivity.PREF_KEY_PHONE_NUMBER ) );
			SettingsActivity.bindPreferenceSummaryToValue( findPreference( SettingsActivity.PREF_KEY_EMAIL ) );

		}
	}

	public static final String PREF_KEY_EMAIL = "email";

	public static final String PREF_KEY_PHONE_NUMBER = "phone_number";

	public static final String PREF_KEY_ADDRESS = "address";

	public static final String PREF_KEY_FULL_NAME = "full_name";

	/**
	 * Determines whether to always show the simplified settings UI, where settings are presented in a single list. When
	 * false, settings are shown as a master/detail two-pane view on tablets. When true, a single pane is shown on
	 * tablets.
	 */
	private static final boolean ALWAYS_SIMPLE_PREFS = false;

	/**
	 * A preference value change listener that updates the preference's summary to reflect its new value.
	 */
	private static Preference.OnPreferenceChangeListener sBindPreferenceSummaryToValueListener = new Preference.OnPreferenceChangeListener()
	{

		public boolean onPreferenceChange( Preference preference, Object value )
		{
			String stringValue = value.toString();

			if ( preference instanceof ListPreference )
			{
				// For list preferences, look up the correct display value in
				// the preference's 'entries' list.
				ListPreference listPreference = (ListPreference) preference;
				int index = listPreference.findIndexOfValue( stringValue );

				// Set the summary to reflect the new value.
				preference.setSummary( index >= 0 ? listPreference.getEntries()[index] : null );

			}

			else
			{
				// For all other preferences, set the summary to the value's
				// simple string representation.
				preference.setSummary( stringValue );
			}
			return true;
		}
	};
}
